Technical Field
The present invention relates to an actuator.
Related Art
Japanese National-Phase Publication No. 2003-529731 describes an actuator provided with a speed reduction mechanism, and this actuator includes a DC motor and a speed reduction mechanism that transmits to an output shaft with a rotation speed about a rotation shaft of the DC motor reduced by a specific speed reduction ratio. Moreover, the speed reduction mechanism is configured including a worm provided on the rotation shaft of the DC motor, a worm gear wheel that meshes with the worm, a beveled gear wheel that is provided coaxial to the worm gear wheel and that is configured rotatable as a unit with the worm gear wheel, and a crown gear wheel that is provided rotatable as a unit with the output shaft and that meshes with the beveled gear wheel.
However, in the actuator described above, the worm gear wheel and the beveled gear wheel are cantilever-supported by a shaft extending from a bracket. It is therefore conceivable that countermeasures such as increases in rigidity of the shaft extending from the bracket will be necessitated in order to suppress axial displacement between the worm gear wheel and the beveled gear wheel during operation of the actuator. This would increase the size of the speed reduction mechanism and increase the frame size of the actuators provided with this speed reduction mechanism.
Moreover, in order to detect a rotation speed and rotation angle of the output shaft of the actuator described above, it is conceivable that a sensor magnet described in Japanese Patent Application Laid-Open (JP-A) No. 2014-42431 might be attached to one end of the output shaft. However, in such cases, it is necessary to provide a circuit board mounted with an element for detecting the magnetic field of the sensor magnet at one axial direction side of the output shaft, increasing the size of the actuator in its axial direction.
In consideration of the above particulars, preferred embodiments provide an actuator capable of suppressing an increase in frame size.